Metallic article



. Jan. 18,'1927.

w 1,614,684 A. PAgz- METALLIC ARTICLE Filed Feb. 15, 1926 Attorneys ,Algdar Pacz Patented Jan. 18, 1927,

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U .ALAJDAR rnoz, or nas'r'oni'vnnann, onro. Y

' METALLIC narrow. f

l Application filed February 15, 1926; Serial no. 883KB; 4

This invention relates to articles of manu-r vfacture'iivhich consist at least in part of aluminum and'has for its object the provi-' sion of -such an article with a surface which is artlstlc in appearance,permanent 1n character," and-protective in effect. It is a wellv known fact that aluminum articles as heretofor'e made have been characterized by the possession of a plain and unembellished metallic surface rather susceptible to tarnish and corrosion and not capable of protection by coatings of metaLpaint, varnish, enamel and the like since the same adhere only very weakly, if at alli the article of the present invention is characterized by the possession. of 'a. surface coating which is both artistic in itself,' highly resistant tocorrosion, abrasion, or removal, and also capable of constituting afirm basis for paint or the like. Y

In the drawings accompanying and forming a part of this application I haveillustrated three diverse forms of metallic arti-. cles symbolic of the numerous range of articles which'fall within my-invention. Fig.

1 illustrates a wall plate for an electricswitch: Fig. 2 a pitcher, and Fig. 3a cigaret case Each is characterized-by the possession of portions 11 where the naked metal is visible interspersed; with irregular spots which range from dark gray to dead black. The mode of producing these articles is described and claimed in my application filed February 10, 1926, Serial No. 87,463, namely: the article; is first made from metallic aluminum or a suitable alloy thereof in the usual manner after which it.

is immersed for a suitable length of time in a hot aqueous solution containing, (1) a soluble fluo-silicate; (2) a salt of a non ferrous. iron-group metal, and (3) an alkali.

salt. The three ingredients I preferably be employed, that other salts of nickel or cobalt can be; employed such as the nitrate, chloride, etc, and that the alkali salt may possess abaseof potash-or soda as well as of ammonia and that other acid. radicals thalrli the nitrate can be employed therewit As a result of the treatment described,.

dark colored spots of various shapesfand sizes'are produced on the surfaces ofthe articles, In the absence of using any stencil or other-shielding meansthis mottled up pearance is produced over the entire surface OFFICE; v

of the article, although itis generally less on the lower face and is'reduced on intoriors, re-entrant'angles, or between closely opposed surfaces It is very'difficult tosecure a complete covering of the article with this deposit, but in the case of most articles the mottled appearance is preferable, and

where protection is the main desideratum it is often possible to secure a comparatively complete coverage of the exposed portions. Some portion of the. article appears always to retain its original metallic surface, although in general the more concentrated the solution or the higher the temperature the smaller are the spots and the finer grained the design, and also the more-rapidly the process is performed. Variations in the relative quantities of the ingredients also affect the size of the grain and the manner of its distribution. Thus an increase in the amount of the fluo-silicate produces a finer grain and a decreasetends to coarsen the same. An increase in the amount of the iron-group metal produces a much similar change in the grain. The effect of the alkali salt appearsmore especially to influence the strength or depth of. the colorization which becomes faint with low concentrations and darker and blackerwith greater strengths.

The resulting coating'is unaffected by any ordinary degree of heating and is highly resistant to abrasion. even that of a steel brush, .the unmodified aluminum surface yielding rather than the modified or coated portion. The articles after receiving treat ment hereinbefore described are taken from the bath, rinsed with water and allowed to dry, whereupon they are complete within the purview of my present invention. *However, they can, if desired, be subjected to fur-- ther treatment, for example'the subjection to the action of water soluble molybdenum salts or other substances to color the remainin metallic portions; or the entire surface can be covered with paint, lacquer, etc. The

- coloring of the unmodified metalcan also be controlled to some extent by allowing other ingredients with the aluminum. For example, the addition to the aluminum of a small quantity, ior example 5% to 15% of silicon, produces a graytone, and by suitably controlling the treatment by concentration temperature, time, etc, as above indicated an effect can be produced much like example the duralumin parts ofair craft present invention exhibit the long-sought resistivity to corrosion and thev containin my hitherto absent ability to hold a coat of paint, and thesame is true as to die-casting alloys whl h generally consist essentially aluminum. and zinc. Accordingly. by the worda1uminum'as used in myclaii ns I mean to designate not only pure alum numaluminums pre-' but also alloys wherein ponderant. Q, While I tion of the surface deposit, is my belief that the surface .of the aluminum is etched donot limit myself to anyf em ressionof theory andwhile it is enerally impossible, or at leastextrem'ely di cult,fto make any chemical analysis of the composi? which consists essentially of an oxide 0 the iron-group metal employed, that is nickel or cobalt; however, it is notimpossible that it" consists'at least in part or-in' some cases ofv metallic nickel or cobalt in a very'fine state of sub-division. articles of manufacture containing my invention may be made of any size or applied to any use-whatever, and that my invention is not avoided by securing a plurality of articles together to produce a larger structure, nor by covering such articles from sight, or by so performing the process as to obtain an unbroken coating on any part of the device. i

. Having thus described my invention what I claim is: y

1. As an article of manufacture, a metallic article consisting at least predominantly of aluminum, the surface of which is etched irregularly and the etched portions coated with an adherent colored deposit.

, 2. An aluminum article having an integral surface layer containing essentially an oxide compound of non-ferrous, iron-group metal which layer is harder and more permanent than the metal ofwhich the article is made.

3. An aluminum article having a hard and permanent coating of oxidized'nonrferrou's -iron-grou metal adherent to at least a part ofits sur ace.

In testimony whereof I hereunto afiix my signature i ALADAR P'Ac z.

It .will be understood that- 

